Effect of size and position of self-expanding transcatheter valve on haemodynamics following valve-in-valve procedure in small surgical bioprostheses: an in-vitro study

AIMS: Valve-in-Valve (ViV) procedure has become a valuable alternative for the treatment of failed surgical bioprostheses (BP) in high risk patients. However, in small BPs, the clinical outcomes have been suboptimal due to high post-procedural gradients. We aimed at examining the effect of size and position of the self-expanding transcatheter heart valve (THV) CoreValve on the hemodynamics of ViV within small BPs. METHODS AND RESULTS: Sizes 23 and 26 mm of the CoreValve were implanted in sizes 19 and 21 mm of 3 BP models: Trifecta, Mitroflow and Epic Supra. The THV was tested in 3 positions: normal (manufacturer recommendation), low (4 mm below normal) and high (4 mm above normal) using a duplicator. Hemodynamics was assessed by Doppler-echocardiography and flowmeter, GOA with high-speed camera. Higher implantation was associated with lower residual gradients (normal position: -9%, high: -25% versus low). High position was, however, associated with increased risk of regurgitation in the Mitroflow and embolization in the Epic Supra. Using 26 mm THV instead of 23 mm was associated with larger EOAs in the Trifecta, smaller in the Mitroflow, and increased risk of embolization in the Epic Supra. CONCLUSIONS: Supra-annular positioning of the CoreValve THV is associated with improved post-ViV hemodynamics in small surgical BPs. The hemodynamic outcomes highly depend on the model and size of surgical BP